Welcome to our sawdust pile, Scott.
Are you trying to run the router base against the edge or side of the board? Most of the time, including putting a profile like an Ogee on the board edge you would run the router base on the flat side of the board with the bit running along the edge. This should be done in a router table or with the bearing running along a template so the bit cuts at a fixed depth. If trying to flush trim a strip of wood that you glued onto the edge of a piece of plywood so both the plywood surface and the glued on solid piece is flush with each other, I sometimes clamp the plywood standing up vertical, with a 2 X 4 spacer and another piece of plywood of the same height sandwhiched together so there is a gap between the two pieces of plywood. I then use a bottom bearing flush cutting bit in my router, with the router base sitting level on top of these two pieces of plywood, to route off the excess of the solid piece. I then turn the plywood being trimmed around in the vice to route off the opposite side to make both edges of the solid piece of wood match the flat surfaces of the plywood. Having two pieces of plywood with the top edges the same height gives you a more stable and level area for the router base to ride on. The router bit will only remove the wood that extend beyond where the bearing touches the plywood.
Please be more detailed in what you are trying to do, so that we can provide a better answer. One of these answers might be right, but if not, more detail of what you are trying to do will be necessary. Pictures might help too.
Central North Carolina